why not to do sth 这个结构对吧?

why not to do sth 这个结构对吧? why not doing sth还是why not do sth还是why not to do sth why not to do sth对吗?waiting why not后面是doing sth还是 to do sth 是Why not to do sth还是Why not do sth? 那个语法是why not to do Sth还是why not do Sth why not do sthwhy not to do sthwhich is right 是why bot do sth.还是why not to do sth. why not 是加to do sth. 还是 动词原形 why not do sth 还是doing sth 是why not do sth.还是why not doing sth. 22题,不是有why not to do sth why don't you do sth22题,不是有why not to do sth why don't you do sth 的句型么? 用why not do sth造句 why not do sth sb放哪? why not do sth ?的用法 短词造句：encourage sb give sb support help sb(to)do sth why not do why do not do sth与why not do sth有什么区别? 有tell sb not to do sth这个短语吗?